Research On Analysis And Simulation Validation Of Spacecraft Attitude Dynamics With Flexible Appendages

Based on coupling dynamics of the spacecraft structure and attitude with flexible appendages, the structure and attitude model of the spacecraft was established with Lagrange Equations based on hybrid coordinate method. The coupling relation between the flexible structure and spacecraft body was analyzed. And the co-simulation method on spacecraft structure and attitude was referred in the paper. The main research works were shown as follows.Firstly, based on the multibody of rigid assumption, the attitude dynamics of dual spinning satellite was induced with Euler equations. The process of attitude determination algorithm with extended Kalman filter was shown in the paper. The kinematics equations of the with attitude dynamics and quaternion were analyzed, and then the attitude control PD algorithm with dual spinning satellite was designed to establish the simulation model by the software Simulink, which was validated the validity of the control algorithm.Secondly, the central difference method and Newmark method, which respectively presented the explicit algorithm and implicit algorithm, were discussed with the process, the characteristic, the stability condition and the applicability in the finite element method. With the software of Ansys, we solved the structure dynamics of satellite-antenna system, and got the natural frequency and modes of the structure,which was not only the basic data for the design of antenna structure, but also could affect the rules between the structure parameters and the response characteristic. When we analyzed the natural frequency and modes of the structure, the coupling mechanism and mechanics essence of satellite-antenna system were discussed in the paper. And the influence of the satellite-antenna by the force in space was discussed; the essentiality of the coupling dynamics analyse between rigid body and flexible body was emphasized.Upon this works, we established the discrete mode coordinate and got the discrete dynamics equations by intercepting the mode of flexible structure. The coupling coefficient (contained the translational coupling coefficient and rotational coupling coefficient) of structure dynamics and attitude dynamics was solved. We could get high precision by this method, and it offered important reference value in the engineering application.At last, we considered the antenna on the dual spinning satellite as flexible appendages to establish the attitude dynamics model by finite element method and rigid body dynamics. The co-simulation of spacecraft attitude and structure was realized. The results showed that it could realize the performance anlyse and evaluation of the total attitude dynamics by the co-simulation method, which could offer some reference value in the engineering application.